Biopsy refers generally to the removal of a tissue sample from a living body for examination. In the field of breast cancer detection and treatment, breast tissue biopsies are often required when a suspicious lesion has been detected. Alternatives to traditional open surgical biopsy have been developed that are less invasive and, therefore, less risky and less costly. Percutaneous breast biopsy refers to the use of a biopsy needle or other instrument, usually long and relatively narrow, to puncture through the skin and capture cellular tissue associated with a breast lesion. The captured tissue is removed from the body and examined for a determination of whether the breast lesion represents a benign or malignant condition.
Percutaneous breast biopsy procedures include fine needle aspiration, core needle biopsy, and vacuum-assisted biopsy. In fine needle aspiration, a fine gauge needle (22 or 25 gauge) and a syringe are used to sample fluid from a breast cyst or remove clusters of cells from a solid mass. In core needle biopsy, small samples of tissue are removed using a hollow “core” needle. In vacuum-assisted biopsy, a special biopsy probe is inserted through a small opening in the skin. Unlike core needle biopsy, which requires several separate needle insertions to acquire multiple samples, the special biopsy probe used during vacuum-assisted biopsy is inserted only once for obtaining multiple samples. Vacuum-assisted biopsy is often referenced by the brand name of the biopsy instrument used, such as MAMMOTOME® from Johnson & Johnson Ethicon Endo-Surgery, MIBB® (Minimally Invasive Breast Biopsy) from Tyco International, Intact™ Breast Lesion Excision System from Intact Medical Systems, and Celero™ from Suros, a Hologic Company.
As used herein, the terms radiologist, physician, surgeon, clinician, and so forth are used interchangeably and generically to refer to medical professionals that analyze medical images and make clinical determinations therefrom, and/or that perform medical procedures under the at least partial guidance of medical imaging systems, it being understood that such person might be titled differently, or might have differing qualifications, depending on the country or locality of their particular medical environment. Percutaneous breast biopsy procedures are often performed with the assistance of ultrasound imaging to facilitate guidance of the biopsy instrument toward and into the breast lesion under study. In so-called freehand ultrasound assisted biopsy, the clinician holds an ultrasound transducer, typically a linear array transducer, against the skin with one hand while manipulating the biopsy instrument with the other hand, the clinician watching the biopsy instrument in real-time on the ultrasound monitor to help guide it to the lesion. In such applications, it is necessary to keep the biopsy needle positioned within the imaged plane in order for it to remain visible on the ultrasound monitor during the procedure.
For the highly skilled clinician, freehand ultrasound assisted biopsy of the breast using a linear array ultrasound transducer can be quickly performed in an out-patient environment, and is much less expensive than other breast biopsy procedures such as x-ray guided stereotactic biopsy and surgical biopsy. Although freehand ultrasound guided biopsy has become a highly popular procedure, it could become even more popular if it were easier to perform. Difficulties begin with the breast surface itself, which can be shifty beneath the linear array ultrasound transducer and even more so because of the slipperiness of the ultrasound gel. The clinician needs to manipulate the linear array ultrasound transducer in one hand and the biopsy needle in the other hand such that the biopsy needle, which can be relatively thin (approximately 1 mm in diameter), is maintained along with the breast lesion within the scan plane of the linear array ultrasound transducer to allow the biopsy needle and lesion to be visible on the ultrasound display. Moreover, the ultrasound display itself is often about three feet away from the breast and difficult to view simultaneously therewith.
It would be desirable to facilitate a freehand ultrasound assisted breast biopsy in a manner that improves one or more of image quality, thoroughness, patient comfort, sample quality, quickness of the process, and accessibility of the process to a wider range of clinicians of different skill levels. It is to be appreciated, however, that while one or more of the preferred embodiments described herein is particularly advantageous for facilitating freehand ultrasound assisted breast biopsy, there is ready applicability to a wide variety of medical imaging applications in which real-time three-dimensional ultrasound scanning is desirable such as, but not limited to, cardiac imaging and fetal imaging, both inside and outside the context of biopsy instrument guidance. Other issues arise as would be readily apparent to one skilled in the art in view of the present disclosure.
According to one preferred embodiment, provided is an apparatus for ultrasonically scanning a tissue volume having a tissue surface. The apparatus comprises a casing configured and dimensioned for single-handed manipulation relative to the tissue surface, and a texturably couplant-porous material sheet extending across an opening of the casing. The texturably couplant-porous material sheet has an outer side and an inner side relative to the casing, the outer side for compressively contacting the tissue surface. The apparatus further comprises an ultrasound transducer positioned against the inner side of the texturably couplant-porous material sheet and being mechanically translatable thereacross for volumetrically scanning the tissue volume therethrough. The incorporation of a texturably couplant-porous material sheet, which can comprise for example a taut fabric sheet or a vented membrane, advantageously tends to at least partially stabilize the tissue surface as the ultrasound transducer is swept thereacross, while also providing for high quality in the images derived from the volumetric ultrasound scans.
According to another preferred embodiment, provided is a method for performing percutaneous biopsy of a target lesion in a tissue volume, comprising manually maintaining a handheld ultrasound probe in compressive contact with a surface of the tissue volume, the handheld ultrasound probe comprising a texturably couplant-porous material sheet having a first side compressively contacting the surface and a second side opposite the first side, the handheld ultrasound probe further comprising an ultrasound transducer repetitively translated across the second side of the texturably couplant-porous material sheet to acquire volumetric ultrasound scans of the tissue volume therethrough. The method further comprises viewing ultrasound images of the target lesion and at least a portion of a freehand percutaneous biopsy instrument on an ultrasound display that is updated in real time with the acquisition of the volumetric ultrasound scans, and guiding the freehand percutaneous biopsy instrument toward the lesion based at least in part on the viewed ultrasound images.
According to another preferred embodiment, provided is an apparatus for ultrasonically scanning a tissue volume, comprising a processor and a handheld ultrasound device. The handheld ultrasound device comprises a casing configured and dimensioned for single-handed manipulation and a mechanically oscillated ultrasound transducer disposed therewithin. The casing has a top surface and a bottom opening. The handheld ultrasound device further comprises a membranous material sheet extending across the bottom opening for compressively contacting a surface of the tissue volume, the ultrasound transducer being mechanically translated across the material sheet while in contact therewith, the ultrasound transducer acquiring ultrasonic scans of the tissue volume downward through the material sheet during the mechanical translation. The processor processes the ultrasonic scans to generate an ultrasound volume representative of an ultrasonic property of the tissue volume. The handheld ultrasound device further comprises a first ultrasound display integral with an upper surface of the casing for displaying a first two-dimensional image derived from the ultrasound volume, and a lid hingably coupled to the casing near the first ultrasound display, the lid being manually closable to cover the first display and manually openable to uncover the first display and remain at a user-adjustable opening angle relative thereto. The handheld ultrasound device further comprises a second ultrasound display integral with an inner surface of the lid for displaying a second two-dimensional image derived from the ultrasound volume when the lid is in an open position. The handheld ultrasound device further comprises an angle detection device for detecting the opening angle of the lid. Preferably, the processor computes the first two-dimensional image by compositing the ultrasound volume in a generally upward direction, and computes the second two-dimensional image by receiving the detected opening angle and compositing the ultrasound volume in a first direction faced by the second ultrasound display as determined by the detected opening angle.